1. Field of the Invention
The invention relates to a portable telephone, and more particularly, to a method and apparatus for generating an alert sound in response to an incoming call.
2. Description of the Related Art
In general, a portable telephone informs a user of an incoming call through generation of an alert sound, vibration or flickering of a lamp. The user selects one of the available modes from these various call alert modes. To implement the alert sound mode, a buzzer has been used in conventional portable telephones.
During the use of the portable telephone it is closely contacted or placed adjacent to an ear by the user. Upon receiving an incoming call, when the portable telephone is closely contacted or placed adjacent to the ear of the user, an abrupt alert sound may sometimes frighten the user or cause damage to the ear. Examples of this instance include when the incoming call is generated before distancing the portable telephone after conversation is completed, and when the portable telephone is placed near the ear before starting conversation after a send key is pressed.
Lately, in particular, the alert sound tends to be produced in various multi-chord bell sounds such as 4 chords and 16 chords, which are produced via a speaker. If such a speaker for outputting the alert sound is installed in the portable telephone separately from a speaker for outputting voice, the portable telephone is restricted in size or design of the outer shape. Therefore, the speaker installed in the receiver is being used in common for outputting a voice and the alert sound.
In such a portable telephone using one speaker installed in the receiver in common for outputting the voice and the alert sound, the abrupt alert sound may surprise the user or cause damage to the ear as severe problems. This is because the alert sound is produced via the speaker in the receiver contacted to the ear by the user and has a sound volume level higher than a buzzer.
As described above, there is a problem that the user may be surprised or suffer damage in the ear due to the abrupt alert sound when the incoming call is received while the receiver of the portable telephone is in close contact or placed adjacent to the ear of the user.